- Thousands of empty pairs of shoes representing children killed by gun violence were lined up outside of the U.S. Capitol on Tuesday as part of a memorial display.

One of the parents in attendance Tuesday was Tom Mauser, whose son was killed in the Columbine school massacre.

Students across the country will walk out of their classrooms for 17 minutes to commemorate the 17 victims who lost their lives in the February 14 shooting at Marjory Stoneman Douglas High School in Parkland, Florida. She said open access to weapons is "giving power to trembling hands". Organizer Emma Ruby-Sachs said she thinks it's a pivotal moment for the movement to end gun violence. Her daughter survived the shooting.

Several mass shootings have occurred since Sandy Hook, including the October 1 tragedy in Las Vegas, a church shooting in Sutherland Springs, Texas, and another school shooting last month in Parkland, Florida.

But the idea has drew condemnation from educators, who said schools will be less safe, not more, with more guns around.

"About five families came that were victims of gun violence", says Oscar Soria, senior campaigner with the protest group. The symbolic shoe demonstrations likely draw inspiration from the renowned memorial at the Hungarian Parliament in Budapest that honors lives lost during the Holocaust.

And, on March 24, there will be another large demonstration against gun violence.